In the target article, human cruelty is linked to intrinsic reinforcement from engaging in the behavior without any recommendations for a research program to validate or test for such reinforcement and its independence from ultimate adaptive outcomes. Suggestions are offered in this commentary for such a program.

We argue that van der Velde's & de Kamps's model does not solve the binding problem but merely shifts the burden of constructing appropriate neural representations of sentence structure to unexplained preprocessing of the linguistic input. As a consequence, their model is not able to explain how various neural representations can be assigned to sentences that are structurally ambiguous.

Mercier and Sperber (M&S) argue that reasoning has evolved primarily as an adjunct to persuasive communication rather than as a basis for consequential choice. Recent research on decision-related regret suggests that regret aversion and concomitant needs for justification may underpin a complementary mechanism that can, if appropriately deployed, convert M&S's facile arguer into an effective decision maker, with obvious evolutionary advantages.

From the stance of cognitive developmental theories, claims that general g is an entity of the mind are compatible with notions about domain-general development and age-invariant individual differences. Whether executive function is equated with general g or fluid g, research into the mechanisms by which development occurs is essential to elucidate the kinds of environmental inputs that engender effective intervention.

Heyman explains useful ways to bring addictive drug use under environmental control. We doubt that relapse is explained by drug features such as immediate reinforcement, clouding of judgment, and so forth. Relapse may require explanation in terms of enduring sensitization of incentive neural substrates, but even if its causal assumptions are wrong, Heyman's model makes useful predictions for behavioral control.

Localist networks are symbolic models, because their nodes refer to extra-mental objects and events. Hence, localist networks can be combined with symbolic computations to form hybrid models. Such models are already familiar and they are likely to represent the dominant type of cognitive model in the next few decades.

From the perspective of modern dream research, Freud's hypotheses regarding repression and dreaming are difficult to evaluate. Several studies indicate that it is possible to study these topics empirically, but it needs a lot more empirical evidence, at least in the area of dream research, before arriving at a unified theory of repression.

Smith et al. show that monkeys and dolphins can respond adaptively under conditions of uncertainty, suggesting that they monitor subjective uncertainty and control their behavior accordingly. Drawing on our own work with humans on the strategic regulation of memory reporting, we argue that, so far, the distinction between monitoring and control has not been addressed sufficiently in metacognitive animal research.

In the original target article (Shanks & St. John 1994), one of our principal conclusions was that there is almost no evidence that learning can occur outside awareness. The continuing commentaries raise some interesting questions, especially about the definition of learning, but do not lead us to abandon our conclusion.

Rahnev & Denison (R&D) argue against normative theories and in favor of a more descriptive “standard observer model” of perceptual decision making. We agree with the authors in many respects, but we argue that optimality (specifically, reward-rate maximization) has proved demonstrably useful as a hypothesis, contrary to the authors’ claims.

Joshua May offers four principles that might serve as the rational foundations of moral judgments. I argue that these principles, if they are independent of affect, are too weak to be the basis of any substantive moral judgment and do not fit with the idea that morality is categorical.